1. Field of Invention
The present invention relates to a heat dissipation structure of a backlight module. More particularly, the present invention relates to a heat dissipation structure integrated into a circuit board of a backlight module.
2. Description of Related Art
A backlight module is one of the fundamental parts in a liquid crystal display (LCD). Since liquid crystal does not emit light itself, the backlight module is needed for providing the required light source. A backlight source commonly used in the backlight module can be a cold cathode fluorescent lamp (CCFL) and an LED (Light-Emitting Diode), etc. In comparison with the CCFL used as the backlight source, the LED has the advantages of small size, long operation life, low driving voltage, low power consumption and excellent shock resistance, etc. However, the efficiency and longevity of the LED are dependent on whether the entire backlight module has good heat-dissipation.
A conventional backlight module often adopts an aluminum substrate or fins for dissipating the heat generated by a LED used as a backlight source. However, the fins disposed on the backlight module make the backlight module too big, and especially, when the power of the LED is increasing, the sizes of the fins required therefore are also increasing. On the other hand, while being used for heat dissipation, the aluminum substrate needs to work together the heat-conductive element of which the size is much larger than that of the LED, so as to sufficiently dissipate the heat generated by the LED. Hence, the heat dissipation structure of the conventional backlight module is too big in size and cannot satisfy the requirements of the products developed towards lightness and smallness,
Besides, the aluminum substrate is quite expensive and cannot be combined with a circuit board as a multi-layered substrate, thus increasing the product fabrication cost and the design difficulty level. Moreover, the conventional skill does not implement electrical isolation between the heat-dissipating and electrically conductive paths of the backlight module, thus likely causing a short circuit resulting in damage on the LCD.